The Audi RS 4 quattro is the top tier and highest performing version of some specific generations of the Audi A4 range of automobiles. It is a sports-focused compact executive car (often called sport compact in some countries), produced by Audi's high-performance private subsidiary quattro GmbH, in limited numbers, for German car manufacturer AUDI AG, part of the larger Volkswagen Group. It slots distinctly above the Audi S4, as the fastest, most sports-focused model based on the A4's "B" automobile platform. The RS 4 made a comeback in 2012, in Avant form only based on the Audi A4 Avant.

The original B5 version was produced only as a five-door five-seat "Avant", Audi's name for an estate car/station wagon. The second version, the B7, was released initially as a four-door five-seat saloon/sedan, with the Avant following a short while later. A two-door four-seat Cabriolet version was subsequently added. Furthermore, their unique internal combustion engines are all front-mounted, and are longitudinally oriented. The transmission is mounted immediately at the rear of the engine in a longitudinal orientation, in the form of a transaxle, and contains both a center and front differential.

The "RS" initials are taken from the German: RennSport—literally translated as "racing sport", and is the Audi marque's highest trim level, positioned above the "S" model specification of Audi's regular model line-up. Like all Audi "RS" cars, the RS 4 pioneers some of Audi's latest advanced technology, and could therefore be described as a "halo vehicle". Furthermore, it is only available with Audi's Torsen-based "trademark" quattropermanent four-wheel drive system.

Its main market competitors include the BMW M3, Mercedes-Benz C63 AMG, and Lexus IS-F.

B5 (Typ 8D, 2000 - 2001)

2000 Audi RS4 front view

2000 Audi RS4 rear view

Audi B5 RS 4 Avant
quattro

Overview

Production

2000–2001

Body and chassis

Body
style

5-door Avant
(estate/wagon)

Platform

Volkswagen Group B5

Related

Audi B5 A4

Audi B5 S4

Powertrain

Engine

2.7 L V6
"biturbo" 2 × DOHC (ASJ/AZR)

Transmission

6-speed manual

Dimensions

Wheelbase

2,607 mm (102.6 in)

Length

4,525 mm (178.1 in)

Width

1,799 mm (70.8 in)

Height

1,386 mm (54.6 in)

Curb
weight

1,620 kg (3,571 lb)

Chronology

Predecessor

Audi RS2 Avant

Successor

Audi B7 RS 4

The original B5 Audi RS 4 Avant quattro (Typ 8D) was introduced by Audi in late 1999, for main production and sale from 2000, as the successor to the Porsche / quattro GmbH joint venture-developed Audi RS2 Avant. The vehicle, like its RS2 predecessor, was available only as an Avant and was built on an existing platform, in this case the Volkswagen Group B5 platform shared with the A4 and S4. Retail price was around DM 103,584. The RS 4 was available for sale in most of Europe, parts of Asia and in some Latin American countries.

Audi produced 6,030 units between 1999 and 2001.

B5 bodywork and styling

Although related to the Audi B5 S4, many of the outer body panels were altered, with wider front and rear wheel arches, to allow for the wider axle trackon the RS 4. With unique front and rear bumpers and side sills, and the rear spoiler from the S4 Avant, the aerodynamic modifications achieved a drag coefficient of Cd 0.34. Although the B5 S4 came in a saloon car body style, the B5 RS 4 was only available in the Avant version.

Luggage space, measured according to the industry standard VDA method was 390 litres (13.8 cu ft) with the rear seats in the upright position, and 1,250 litres (44.1 cu ft) with the seats folded flat.

B5 powertrain

Carbon fiber cover of the Audi B5 RS 4 2.7 V6 "biturbo" engine

The engine was developed from the 2.7 litre 90° V6 'biturbo' used in the B5 S4. It displaced 2,671 cubic centimetres (163.0 cu in) and had five valves per cylinder. The parts code prefix was 078 and the identification codes were: early version, 2000 (EU2 compliant): ASJ, and later version, 2000-01 (to EU3 standard): AZR. This engine was developed and manufactured in the UK by Cosworth Technology (now known as MAHLE Powertrain). It featured enlarged intake and smaller exhaust ports on the two Cosworth cast aluminium alloy ALSi7mg cylinder heads, two parallel BorgWarner K04-series turbochargers, two larger side-mounted intercoolers (SMICs), dished piston crowns, stronger connecting rods, larger intake ducting, enlarged exhaust system, and a re-calibrated engine management system. The modifications increased the engine's output from 195 kilowatts (265 PS; 261 bhp) and 400 newton metres (295 lbft) of torque in S4 form to 280 kilowatts (381 PS; 375 bhp) at 7,000 revolutions per minute (rpm) and 440 newton metres (325 lbft) at 6,000 rpm. The engine was controlled by a Bosch Motronic ME 7.1 electronic engine control unit (ECU), using a Bosch 'E-Gas' electronic drive by wire throttle. The engine had multipoint sequential fuel injection, a MAF, six individual single-spark coils and NGK longlife spark plugs. The engine oil was cooled by a dual oil:water cooler and an oil:air cooler.

Even with a kerb weight weight of 1,620 kilograms (3,571 lb), the RS 4's powerful engine gave it the performance of a sports car. 100 kilometres per hour (62.1 mph) could be reached from rest in 4.9 seconds, 160 kilometres per hour (99.4 mph) in 11.3 seconds, and 200 kilometres per hour (124.3 mph) in 17.0 seconds. Top speed was electronically limited to 262 kilometres per hour (162.8 mph).

B5 brakes, wheels and tyres

Brakes were also developed jointly in house by Audi's quattro GmbH, not by Porsche as with its predecessor, the RS 2. At the front they were radially vented and floating cast iron discs, 360 millimetres (14.2 in) diameter and 32 millimetres (1.26 in) thick, with double-piston floating calipers, and at the rear 312 millimetres (12.3 in) by 22 millimetres (0.87 in) discs with a single-piston floating caliper. The RS 4 needed less than 50 metres (160 ft) to come to a full stop from a speed of 110 kilometres per hour (68 mph).

There was no RS 4 built on the Audi "B6" platform that served as the basis for the Audi A4 between 2001 and 2005. However, after a long hiatus, the second Audi RS 4 quattro (Typ 8E), was built on Audi's "B7" A4 platform, by quattro GmbH in Neckarsulm, Germany. It was unveiled in February 2005 at Audi's 'quattro Night' celebration at the company headquarters in Ingolstadt, Germany.

The RS 4 became available to European customers in mid-2006. It was introduced at the 2006 North American International Auto Show in January, and arrived in June 2006 in North America. The production run of the B7 RS 4 was 2006 to 2008 inclusive, although only 2007 and 2008 model year were sold in the United States. To date, approximately 10,000 B7 RS 4s have been built, of which around 2,500 are in the USA.

The B7 RS 4 Cabriolet, available in Europe from late 2006 to 2008, was made available as a model year 2008 vehicle in the USA.

Audi factory numbers indicate that the B7 RS 4 saloon can accelerate from 0 to 100 kilometres per hour (0.0 to 62.1 mph) in 4.8 seconds, and arrive at 0 to 200 kilometres per hour (0.0 to 124.3 mph) in 16.6 seconds. Most European magazines recorded results in line with the November 2009 comparison of "ultimate sedans", in Road & Track, which recorded a 0 to 60 time of 4.5 seconds. This is consistent with the pattern of conservatism that is usually found in Audi's official performance numbers. For the Avant, 0 to 100 kilometres per hour (0.0 to 62.1 mph) is reached in 4.9 seconds. Top speed for all variants is "officially" electronically limited to 250 kilometres per hour (155.3 mph), though some owners have reported that the speed limiter is rather "liberal", conforming to the pattern of previous Audi "RS" cars, with genuine top speeds of 270 kilometres per hour (170 mph) being recorded.

B7 bodywork and styling

The B7 RS 4 is an almost complete departure from previous Audi "RS" cars, as it was initially available as a four-door five-seat saloon/sedan; with a five-door five-seat Avant (estate/wagon), and two-door four-seat Cabriolet (convertible) versions arriving later. Only the Audi RS 6 had taken this similar route (saloon and Avant) before; the previous RS 4 and RS 2 were available exclusively as Avants.

Constructed from fully galvanised steel in a monocoque (unitary/unibody) design, the B7 RS 4 uses lightweight aluminium for its front wings (fenders) and bonnet (hood). The saloon version features a drag coefficient (Cd) of 0.31, from a frontal area of 2.17 m2.

Like its B5 predecessor, visually, the B7 RS 4 differs from its related B7 S4, by having even wider flared front and rear wheel arches (fenders), to allow for a wider axle track. Over the B7 A4, it also includes two larger frontal side air intakes (for the two additional side-mounted coolant radiators). The trim on the saloon and roof rails on the estate are chrome as standard but can also be found in black with the addition of the Optic Pack which includes a black front grill, all exterior trim and black roof rails on the estate version. The B7 RS 4 also includes an optional adaptive headlights to complement the standard "Xenon Plus" (Bi-Xenon arc) High Intensity Discharge (HID) headlamps, which swivel around corners in conjunction with steering wheel movements. Also standard are daytime running lights (DRLs), found within the main headlamp housings, identical to its related B7 A4 and S4, and use a conventional tungsten filament bulb. An acoustic parking system with front and rear sensors is also a standard fitment. Unique carbon fibre interior trims, along with a lap timer within the central Driver Information System (DIS), aluminium pedal caps and footrest, and RS 4 logos complete the look.

In the saloon, luggage space, measured according to the VDA 'block method', is 460 litres (16.2 cu ft) with the rear seats in the upright position, and 720 to 833 litres (25.4 to 29.4 cu ft) with the seats folded flat (dependent on specification). For the Avant, 442 litres (15.6 cu ft) is available with the seats upright (under the retractable load cover), and 1,354 litres (47.8 cu ft) being available with the rear seats folded flat (loaded to the roofline). Kerb weight of the saloon variant starts at 1,650 kilograms (3,638 lb) (dependent on specification).

A BOSE ten-speaker sound system, with 190 watt output and automatic dynamic noise compensation (which replaces the 'GALA' found on earlier units), with "Concert II" radio and single CD player is standard in car entertainment (ICE) equipment. Factory fitted ICE options to complement the standard BOSE include the "Symphony II" system which features twin radio tuners, a single-slot loading six-CD changer and a cassette player all integrated into a double-DIN sized unit. Navigation option is the RNS-E "Audi Navigation System plus" DVD-ROM GPS satellite navigation, which includes a folding widescreen 6.5-inch screen, two SD-memory card readers, and MMI-like logic control.

Two-stage driver and front seat passenger frontal airbags are standard, as is Audi's "sideguard" head protection curtain airbag system. This latter system completely covers all of the side windows, from the front 'A pillar' to the rear "C-" or "D pillars". The body-hugging Recaro shell-type RS race bucket seats (not available in North American markets), complete with electrically inflatable upper and lower side bolsters and adjustable lumbar support, are constructed so as not to need lower side airbags to comply with European crash safety standards. In North America, the only front seats available are the more traditional Recaro seats (identical to those in the B6 and B7 S4), which include lower side airbags; these were also available as a no-cost option in other markets. Lower side airbags are optional for the standard-fit Recaro rear seats. Front, and outer rear seatbelts include pyrotechnic belt pretensioners, whilst all belts include an excess load limit function.

B7 powertrain

The engine of the B7 RS 4 is based on the existing all-alloy 4.2 V8 from the B6 S4, and shares many parts, and Fuel Stratified Injection, with the 4.2 FSI V8 engine in the Q7. The engine includes new cylinder block construction, and is a highly reworked, high-revving variant (redline at 8,000 rpm; rev limit of 8,250 rpm).

The parts code and version is 079.D and the identification code is BNS.

The engine has increased crankcase breathing, a low-pressure fuel return system and a baffled oil sump, to prevent engine lubricant cavitation at high engine speeds and high-G cornering. It has four valves per cylinder (instead of five on the earlier variant) and two overhead camshafts on each cylinder bank (so it is 'quad cam') and these are driven by roller chains with variable valve timing for both inlet and exhaust camshafts, along with a cast magnesium alloy fixed tract length intake manifold with adjustable tumble flaps (to improve low engine speed combustion). On 98 RON (93 AKI) Super-Unleaded petrol it produces 309 kilowatts (420 PS; 414 bhp) at 7,800 rpm giving it a specific power output of 74.2 kW (100.9 PS; 99.5 bhp) per litre. Based on a kerb weight of 1,680 kilograms (3,704 lb), this results in a power-to-weight ratio of 184 watts per kilogram. This engine also produces 430 newton metres (317 lbft) of torque at 5,500 rpm, 90 percent of the total torque being available between 2,250 and 7,600 rpm. (Using lower 95 RON (91 AKI) standard unleaded fuel slightly reduces engine output, and therefore performance, and slightly worsens fuel economy). Exhaust gas escapes through two '4-into-2-into-1' fan-branch alloy steel exhaust manifolds and four high-flow metallic sports catalytic converters, into twin oval tail pipes with integral dynamic silencer/muffler valves. The engine is controlled by two Bosch DI-Motronic MED 9.1 electronic engine control units (working as 'master' and 'slave', because of the high-revving nature of the engine), and uses Bosch 'E-Gas' electronic throttle control (also known as drive by wire), comprising throttle device, accelerator-pedal module, and ECU. The ignition system uses eight individual single-spark coils, using mapped direct ignition, with Bosch single iridium electrode or NGK triple-electrode long-life spark plugs. Ignition timing is monitored with the aid of four knock sensors. The engine complies with the Euro4 European emission standards. The saloon version produces 322-329 grams of CO2 per kilometre (g/km), and the Avant starts from 324 g/km.

The Audi B7 RS 4 was the only "RS" Audi powered by a naturally aspirated engine until the Audi RS5 was presented at the 2010 Geneva Motor Show. The RS5 also uses a 4.2 litre high revving V8. The RS5 also dropped the Getrag 6-speed manual in favour of a 7-speed "S tronic" dual clutch semi-automatic.

quattro

Another focus of the B7 RS 4 was on the introduction of the latest development of Audi's 'trademark' quattro permanent four-wheel drive system. This utilised the 'third generation' asymmetric/dynamic Torsen T-3 'automatic torque biasing' (ATB) centre differential, featuring a 'default' 40:60 front-to-rear torque split under normal conditions. Audi stressed that this would result in a more neutral response in corners, and a more dynamic driving experience. Also, a more aggressive Torque Bias Ratio (TBR) was used, and set to 4:1, as opposed to 2:1 (and later variants 3:1 TBR) on standard A4. That means that one side of the differential can handle up to 80%, while the other side would have to only handle 20% of applied torque.

Front and rear axle differentials are conventional "open" types, with a final drive ratio of 4.111.

Traction is assisted by way of Audi's "Electronic Differential Lock" (EDL), which is a specific function of the Robert Bosch GmbH ESP 8.0 Electronic Stability Programme system. EDL monitors the rotational speeds of the left and right wheels across an individual axle, and if one wheel should rotate faster than the other (exceeding the pre-defined parameters), indicating loss of traction, or "wheel spin" on one wheel, the EDL applies the brakes to that individual spinning wheel, and thus results in transferring torque across the open differential to the wheel on the other side deemed to have grip, hence traction. Also included in the ESP 8.0 is "Anti Slip Regulation" (ASR)—Audi's name for Traction Control System.

The result of all these features is that under normal circumstances (driving straight on dry or even wet road surfaces) the car never loses traction, even when accelerating at full throttle in the first gear.

B7 suspension and steering

The B7 RS 4 also incorporates Audi's "Dynamic Ride Control" (DRC) "Sports Suspension" mechanism. The dampers (shock absorbers) are made for Audi by KW, and central reservoirs/valves made by KYB (Kayaba). In the RS 4 suspension, a fluid hydraulic linkage between diagonally opposing front and rear suspension dampers (left front to right rear, and vice-versa) is used to counteract vehicle pitch and roll. Lightweight magnesium/aluminium alloy multi-link suspension arms (four arm with virtual steering axis up front, and trapezoidal arm with unequal length track control arms at the rear) locate each hub/brake/roadwheel assembly in a controllable fashion, whilst minimising unsprung masses. Lightweight hollow tubular anti-roll bars are standard front and rear. Compared to standard B7 A4 models, the RS 4 features a 30 millimetres (1.2 in) lower ride height. An optional "Sports Suspension Plus" lowers the car by a further 10 millimetres (0.4 in), and marginally further stiffens the damper rates.

Axle track has also been increased over standard A4s; the front widened by 37 millimetres (1.5 in), to 1,559 millimetres (61.4 in) and the rear by 47 millimetres (1.9 in) to 1,569 millimetres (61.8 in).

B7 brakes, wheels and tyres

The standard brakes on the RS 4 are of two-piece construction. The cast iron discs are cross-drilled and radially ventilated and float on aluminium alloy disc hubs. The two-piece disc construction reduces unsprung mass and also reduces the transmission of heat generated by the brakes to the wheel bearings.

The front discs are 365 millimetres (14.4 in) in diameter and 34 millimetres (1.34 in) thick, and use gloss black Brembo monoblock eight-opposed-piston fixed calipers. These and the transmission are supplied with a cooling airflow directed from NACA ducts located in the engine front undertray.

A specifically 'tuned' "sport-biased" Bosch ESP 8.0 Electronic Stability Programme is standard, and includes Anti-lock Braking System (ABS) and Electronic Brakeforce Distribution(EBD), and Brake Assist (BA). This ESP system has three user-selectable settings: the standard default full protection mode, increased slip mode (which turns off the ASR and EDL), and ESP fully off. A useful feature of the ESP 8.0 is 'disc wiping', whereby in wet weather the ESP system applies the brakes frequently but momentarily. This removes water from the disc and pad surfaces, and helps to maintain the braking performance of dry weather. This operation is undetectable by the driver.

In the UK and Japan, the standard wheels are 19 inch alloy wheels (9Jx19" ET29 "7-arm double spoke") with 255/35 ZR19 96Y XL (eXtraLoad) high performance tyres. This 19" wheel and tyre package was an option for the North American, and some European markets. Factory supplied tyres included Continental SportContact 3, Michelin Pilot Sport PS2, or Pirelli P-Zero Rosso — although many owners have questioned the load-carrying abilities of the Pirellis (from unexplained sidewall failures and dubious dynamic stability), opting for the more durable Michelins at replacement time. A no-cost option of 18 inch alloy wheels (8½Jx18" ET24 "5-spoke design") with 255/40 ZR18 Y XL tyres was also available, and these are standard in North American markets. A winter wheel and tire package was also available as an option, and included 245/40 R18 96V Dunlop SP WinterSport 3D tyres.

A direct-acting Tyre Pressure Monitoring System (TPMS) is standard fitment. This system monitors the pressure in all four tyres every three seconds, and when any loss in pressure is detected, audible and visual warnings are given to alert the driver via the Driver Information System (DIS) in a timely manner.

Other B7 notable features

Other notable features to be found as standard equipment on cars for non-North American markets are the smaller, flat bottomed steering wheel (complete with "Sport" button), body-hugging Recaro shell-type race bucket seats complete with electrically inflatable upper and lower side bolsters, and carbon-ceramic brakes. The B7 Audi RS 4 sold in Europe has roll-up windows for the rear doors although its USA-market counterpart has power windows for all doors.

B7 crash testing

The North American Insurance Institute for Highway Safety (IIHS) crash tested the B7 RS 4s sibling, the B7 A4, and awarded it "Double Best Pick" for frontal and side crashes—beating illustrious rivals such as the BMW 3 Series, the Mercedes-Benz C-Class, and even the Volvo S60.

B7 awards

The Audi RS 4 won Top Gear's Most Surprising Car of the Year in 2005. In 2007, the Audi RS 4 was the winner in the "World Performance Car" category of the International World Car of the Year (WCOTY). It beat illustrious rivals, including its larger sibling, the Audi C6 S6, the Porsche 911 Turbo, Porsche 911 GT3, Ferrari 599 GTB, and Jaguar XKR.

The Audi RS 4 Avant uses the same normally aspirated V8 engine that powers the RS 5 Coupe. The 4,163 cc powerplant produces 450 hp Its torque of 317.15 lbft is available from 4,000 to 6,000 rpm. The RS 4 Avant accelerates from zero to 100 km/h (62 mph) in 4.7 seconds on its way to a governed top speed of 250 km/h (155 mph).

Top traction: quattro drive with crown-gear center differential Like every RS model from Audi, the RS 4 Avant comes standard with quattro permanent all-wheel drive. The heart of this system is the crown-gear center differential. This compact and lightweight component can vary the distribution of power between the front and rear axles immediately, smoothly and over a wide range, with up to 70 percent flowing to the front or as much as 85 percent to the rear. The default 40:60 ratio of the rear-biased configuration ensures sporty handling.

The self-locking crown-gear center differential works together with the torque vectoring system, which acts on all four wheels. If the load on the inside wheel is reduced too much while the car is being driven dynamically, the torque vectoring system brakes it slightly before unintended slip can occur. Audi offers the sport differential, which uses two superposition stages to actively distribute the power between the rear wheels, as an option.

B8 (2012-)

2013 Audi RS4 Avant front view

2013 Audi RS4 Avant rear view

Audi B8 RS 4 Avant
quattro

Overview

Production

2012-present

Body and chassis

Body
style

5-door Avant
(estate/wagon)

Platform

B8

Related

Audi B8 A4

Audi B8 S4

Audi A5

Audi S5

Audi Q5

Powertrain

Engine

4.2 L (4,163 cc) V8
FSI 32 valve

Transmission

7 S-Tronic

Dimensions

Wheelbase

2,811 mm (110.7 in)

Length

4,719 mm (185.8 in)

Width

1,826 mm (71.9 in)

Height

1,415 mm (55.7 in)

Curb
weight

1795 kg (3957 lb)

Chronology

Predecessor

Audi B7 RS 4

The Audi B8 RS4 is available in an Avant only body style using the Volkswagen MLB platform. It is also only available with the Dual Clutch S-tronic gearbox configuration, allowing the car to achieve 0-60 mph in 4.7 seconds. Amongst the options available for the B8 RS4, are ceramic brakes, allowing the car to perform heavy braking without having brake fade.

Motorsport

Speed World Challenge

The B7 RS 4 was planned to replace the C5 RS6 in the SCCA Speed World Challenge, but after Champion Racing had prepared the car, it was decided not to compete in the series, due to rule changes imposed by the Sports Car Club of America (SCCA) on Audi concerning 4WD systems, wheels size, and engine power output. Rather than scrapping the fully built Speed World Challenge RS 4, Champion and Audi used the car as a part of the American Le Mans Series Vitesse Program, which highlights the technology link between race cars and conventional series production road cars.

Euro Superstars

Steven Goldstein at the wheel of a race-prepared RS 4

Six RS 4s are openly campaigned in the Superstars Series by Audi Sport Italia. Audi RS 4 quattro driver Gianni Morbidelli won the 2007 and 2008 championships.